An investigation of water status in gelatin methacrylate hydrogels by means of water relaxometry and differential scanning calorimetry

• Published in: Journal of materials chemistry. B, Materials for biology and medicine Vol. 12; no. 26; pp. 6328 - 6341
• Main Authors: Chang, Chun-Wei, Dargaville, Bronwin L, Momot, Konstantin I, Hutmacher, Dietmar W
• Format: Journal Article
• Language: English
• Published: England Royal Society of Chemistry 03.07.2024
• Subjects: Biocompatible Materials - chemistry; Biomaterials; Biomedical materials; Biomolecules; Bound water; Calorimetry; Calorimetry, Differential Scanning; Crosslinking; Differential scanning calorimetry; Diffusion coefficient; Drug delivery; Gelatin; Gelatin - chemistry; Hydrogels; Hydrogels - chemistry; Hydrogen bonding; Magnetic Resonance Spectroscopy; Methacrylates - chemistry; Moisture content; Molecular structure; NMR; Nuclear magnetic resonance; Regenerative medicine; Relaxation time; Tissue engineering; Water; Water - chemistry; Water content
• ISSN: 2050-750X; 2050-7518; 2050-7518
• DOI: 10.1039/d4tb00053f

The relationship between molecular structure and water dynamics is a fundamental yet often neglected subject in the field of hydrogels for drug delivery, bioprinting, as well as biomaterial science and tissue engineering & regenerative medicine (TE&RM). Water is a fundamental constituent of hydrogel systems and engages via hydrogen bonding with the macromolecular network. The methods and techniques to measure and reveal the phenomena and dynamics of water within hydrogels are still limited. In this work, differential scanning calorimetry (DSC) was used as a quantitative method to analyze freezable (including free and freezable bound) and non-freezable bound water within gelatin methacrylate (GelMA) hydrogels. Nuclear magnetic resonance (NMR) is a complementary method for the study of water behavior and can be used to measure the spin-relaxation of water hydrogen nuclei, which is related to water dynamics. In this research, nuclear magnetic resonance relaxometry was employed to investigate the molecular state of water in GelMA hydrogels using spin-lattice ( T 1 ) and spin-spin ( T 2 ) spin-relaxation time constants. The data displays a trend of increasing bound water content with increasing GelMA concentration. In addition, T 2 values were further applied to calculate microviscosity and translational diffusion coefficients. Water relaxation under various chemical environments, including different media, temperatures, gelatin sources, as well as crosslinking effects, were also examined. These comprehensive physical data sets offer fundamental insight into biomolecule transport within the GelMA hydrogel system, which ultimately are important for drug delivery, bioprinting, as well as biomaterial science and TE&RM communities. Nuclear magnetic resonance relaxometry and differential scanning calorimetry give fundamental insight into the molecular dynamics of water interactions in gelatin-methacrylate hydrogels, with implications for a multitude of biomaterials applications.